EP4173195A1

EP4173195A1 - Physical uplink control channel resource indication for sidelink hybrid automatic repeat request feedback

Info

Publication number: EP4173195A1
Application number: EP21733352.5A
Authority: EP
Inventors: Hua Wang; Sony Akkarakaran; Tao Luo; Junyi Li
Original assignee: Qualcomm Inc
Current assignee: Qualcomm Inc
Priority date: 2020-06-26
Filing date: 2021-05-19
Publication date: 2023-05-03
Also published as: CN115777182A; US20210409166A1; KR20230028285A; WO2021263260A1

Abstract

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a first user equipment (UE) may receive an indication of a physical uplink control channel (PUCCH) resource for providing hybrid automatic repeat request (HARQ) feedback for a sidelink data transmission from a second UE. The first UE may transmit the HARQ feedback for the sidelink data transmission on the PUCCH resource. Numerous other aspects are provided.

Description

PHYSICAL UPLINK CONTROL CHANNEL RESOURCE INDICATION FOR SIDELINK HYBRID AUTOMATIC REPEAT REQUEST FEEDBACK

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This Patent Application claims priority to U.S. Provisional Patent Application No. 63/044,900, filed on June 26, 2020, and entitled “PHYSICAL UPLINK CONTROL CHANNEL RESOURCE INDICATION FOR SIDELINK HYBRID AUTOMATIC REPEAT REQUEST FEEDBACK,” and U.S. Nonprovisional Patent Application No. 17/303,006, filed on May 18, 2021, and entitled “PHYSICAL UPLINK CONTROL CHANNEL RESOURCE INDICATION FOR SIDELINK HYBRID AUTOMATIC REPEAT REQUEST FEEDBACK,” which are hereby expressly incorporated by reference herein.

FIELD OF THE DISCLOSURE

[0002] Aspects of the present disclosure generally relate to wireless communication and to techniques and apparatuses for a physical uplink control channel resource indication for sidelink hybrid automatic repeat request feedback.

BACKGROUND

[0003] Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, and broadcasts. Typical wireless communication systems may employ multiple-access technologies capable of supporting communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power, or the like). Examples of such multiple-access technologies include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency-division multiple access (FDMA) systems, orthogonal frequency-division multiple access (OFDMA) systems, single-carrier frequency-division multiple access (SC- FDMA) systems, time division synchronous code division multiple access (TD-SCDMA) systems, and Long Term Evolution (LTE). LTE/LTE- Advanced is a set of enhancements to the Universal Mobile Telecommunications System (UMTS) mobile standard promulgated by the Third Generation Partnership Project (3GPP).

[0004] A wireless network may include a number of base stations (BSs) that can support communication for a number of user equipment (UEs). A UE may communicate with a BS via the downlink and uplink. “Downlink” (or “forward link”) refers to the communication link from the BS to the UE, and “uplink” (or “reverse link”) refers to the communication link from the UE to the BS. As will be described in more detail herein, a BS may be referred to as a Node B, a gNB, an access point (AP), a radio head, a transmit receive point (TRP), a New Radio (NR) BS, a 5G Node B, or the like.

[0005] The above multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different user equipment to communicate on a municipal, national, regional, and even global level. NR, which may also be referred to as 5G, is a set of enhancements to the LTE mobile standard promulgated by the 3GPP. NR is designed to better support mobile broadband Internet access by improving spectral efficiency, lowering costs, improving services, making use of new spectrum, and better integrating with other open standards using orthogonal frequency division multiplexing (OFDM) with a cyclic prefix (CP) (CP-OFDM) on the downlink (DL), using CP- OFDM and/or SC-FDM (e.g., also known as discrete Fourier transform spread OFDM (DFT-s- OFDM)) on the uplink (UL), as well as supporting beamforming, multiple-input multiple-output (MIMO) antenna technology, and carrier aggregation. As the demand for mobile broadband access continues to increase, further improvements in LTE, NR, and other radio access technologies remain useful.

SUMMARY

[0006] In some aspects, a method of wireless communication performed by a first user equipment (UE) includes: receiving an indication of a physical uplink control channel (PUCCH) resource for providing hybrid automatic repeat request (HARQ) feedback for a sidelink data transmission from a second UE; and transmitting the HARQ feedback for the sidelink data transmission on the PUCCH resource.

[0007] In some aspects, a method of wireless communication performed by a base station includes: transmitting a downlink communication that includes an indication of a PUCCH resource for a first UE to provide HARQ feedback for a sidelink data transmission from a second UE; and receiving the HARQ feedback for the sidelink data transmission from the first UE on the PUCCH resource.

[0008] In some aspects, a first UE for wireless communication includes: a memory; and one or more processors coupled to the memory, the memory and the one or more processors configured to: receive an indication of a PUCCH resource for providing HARQ feedback for a sidelink data transmission from a second UE; and transmit the HARQ feedback for the sidelink data transmission on the PUCCH resource.

[0009] In some aspects, a base station for wireless communication includes: a memory; and one or more processors coupled to the memory, the memory and the one or more processors configured to: transmit a downlink communication that includes an indication of a PUCCH resource for a first UE to provide HARQ feedback for a sidelink data transmission from a second UE; and receive the HARQ feedback for the sidelink data transmission from the first UE on the PUCCH resource.

[0010] In some aspects, a non-transitory computer-readable medium storing a set of instructions for wireless communication includes: one or more instructions that, when executed by one or more processors of a first UE, cause the first UE to: receive an indication of a PUCCH resource for providing HARQ feedback for a sidelink data transmission from a second UE; and transmit the HARQ feedback for the sidelink data transmission on the PUCCH resource.

[0011] In some aspects, a non-transitory computer-readable medium storing a set of instructions for wireless communication includes: one or more instructions that, when executed by one or more processors of a base station, cause the base station to: transmit a downlink communication that includes an indication of a PUCCH resource for a first UE to provide HARQ feedback for a sidelink data transmission from a second UE; and receive the HARQ feedback for the sidelink data transmission from the first UE on the PUCCH resource.

[0012] In some aspects, an apparatus for wireless communication includes: means for receiving an indication of a PUCCH resource for providing HARQ feedback for a sidelink data transmission from a second apparatus; and means for transmitting the HARQ feedback for the sidelink data transmission on the PUCCH resource.

[0013] In some aspects, an apparatus for wireless communication includes: means for transmitting a downlink communication that includes an indication of a PUCCH resource for a first UE to provide HARQ feedback for a sidelink data transmission from a second UE; and means for receiving the HARQ feedback for the sidelink data transmission from the first UE on the PUCCH resource.

[0014] Aspects generally include a method, apparatus, system, computer program product, non-transitory computer-readable medium, user equipment, base station, wireless communication device, and/or processing system as substantially described herein with reference to and as illustrated by the drawings and specification.

[0015] The foregoing has outlined rather broadly the features and technical advantages of examples according to the disclosure in order that the detailed description that follows may be better understood. Additional features and advantages will be described hereinafter. The conception and specific examples disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present disclosure. Such equivalent constructions do not depart from the scope of the appended claims. Characteristics of the concepts disclosed herein, both their organization and method of operation, together with associated advantages will be better understood from the following description when considered in connection with the accompanying figures. Each of the figures is provided for the purposes of illustration and description, and not as a definition of the limits of the claims. [0016] While aspects are described in the present disclosure by illustration to some examples, those skilled in the art will understand that such aspects may be implemented in many different arrangements and scenarios. Techniques described herein may be implemented using different platform types, devices, systems, shapes, sizes, and/or packaging arrangements. For example, some aspects may be implemented via integrated chip embodiments or other non-module- component based devices (e.g., end-user devices, vehicles, communication devices, computing devices, industrial equipment, retail/purchasing devices, medical devices, or artificial intelligence-enabled devices). Aspects may be implemented in chip-level components, modular components, non-modular components, non-chip-level components, device-level components, or system-level components. Devices incorporating described aspects and features may include additional components and features for implementation and practice of claimed and described aspects. For example, transmission and reception of wireless signals may include a number of components for analog and digital purposes (e.g., hardware components including antennas, RF chains, power amplifiers, modulators, buffers, processor(s), interleavers, adders, or summers). It is intended that aspects described herein may be practiced in a wide variety of devices, components, systems, distributed arrangements, or end-user devices of varying size, shape, and constitution.

BRIEF DESCRIPTION OF THE DRAWINGS [0017] So that the above-recited features of the present disclosure can be understood in detail, a more particular description, briefly summarized above, may be had by reference to aspects, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only certain typical aspects of this disclosure and are therefore not to be considered limiting of its scope, for the description may admit to other equally effective aspects. The same reference numbers in different drawings may identify the same or similar elements.

[0018] Fig. 1 is a diagram illustrating an example of a wireless network, in accordance with the present disclosure.

[0019] Fig. 2 is a diagram illustrating an example of a base station in communication with a UE in a wireless network, in accordance with the present disclosure.

[0020] Fig. 3 is a diagram illustrating an example of sidelink communications, in accordance with the present disclosure.

[0021] Fig. 4 is a diagram illustrating an example of sidelink communications and access link communications, in accordance with the present disclosure. [0022] Figs. 5 and 6 are diagrams illustrating examples associated with physical uplink control channel (PUCCH) resource indication for sidelink hybrid automatic repeat request (HARQ) feedback, in accordance with the present disclosure.

[0023] Figs. 7 and 8 are diagrams illustrating example processes associated with PUCCH resource indication for sidelink HARQ feedback, in accordance with the present disclosure. [0024] Figs. 9 and 10 are diagrams of example apparatuses for wireless communication, in accordance with the present disclosure.

DETAILED DESCRIPTION

[0025] Various aspects of the disclosure are described more fully hereinafter with reference to the accompanying drawings. This disclosure may, however, be embodied in many different forms and should not be construed as limited to any specific structure or function presented throughout this disclosure. Rather, these aspects are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. Based on the teachings herein, one skilled in the art should appreciate that the scope of the disclosure is intended to cover any aspect of the disclosure disclosed herein, whether implemented independently of or combined with any other aspect of the disclosure. For example, an apparatus may be implemented or a method may be practiced using any number of the aspects set forth herein. In addition, the scope of the disclosure is intended to cover such an apparatus or method which is practiced using other structure, functionality, or structure and functionality in addition to or other than the various aspects of the disclosure set forth herein. It should be understood that any aspect of the disclosure disclosed herein may be embodied by one or more elements of a claim.

[0026] Several aspects of telecommunication systems will now be presented with reference to various apparatuses and techniques. These apparatuses and techniques will be described in the following detailed description and illustrated in the accompanying drawings by various blocks, modules, components, circuits, steps, processes, algorithms, or the like (collectively referred to as “elements”). These elements may be implemented using hardware, software, or combinations thereof. Whether such elements are implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. [0027] It should be noted that while aspects may be described herein using terminology commonly associated with a 5G or NR radio access technology (RAT), aspects of the present disclosure can be applied to other RATs, such as a 3G RAT, a 4G RAT, and/or a RAT subsequent to 5G (e.g., 6G).

[0028] Fig. 1 is a diagram illustrating an example of a wireless network 100, in accordance with the present disclosure. The wireless network 100 may be or may include elements of a 5G (NR) network and/or an LTE network, among other examples. The wireless network 100 may include a number of base stations 110 (shown as BS 110a, BS 110b, BS 110c, and BS 1 lOd) and other network entities. A base station (BS) is an entity that communicates with user equipment (UEs) and may also be referred to as an NR BS, a Node B, a gNB, a 5G node B (NB), an access point, a transmit receive point (TRP), or the like. Each BS may provide communication coverage for a particular geographic area. In 3GPP, the term “cell” can refer to a coverage area of a BS and/or a BS subsystem serving this coverage area, depending on the context in which the term is used.

[0029] A BS may provide communication coverage for a macro cell, a pico cell, a femto cell, and/or another type of cell. A macro cell may cover a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access by UEs with service subscription. A pico cell may cover a relatively small geographic area and may allow unrestricted access by UEs with service subscription. A femto cell may cover a relatively small geographic area (e.g., a home) and may allow restricted access by UEs having association with the femto cell (e.g., UEs in a closed subscriber group (CSG)). A BS for a macro cell may be referred to as a macro BS. A BS for a pico cell may be referred to as a pico BS. A BS for a femto cell may be referred to as a femto BS or a home BS. In the example shown in Fig. 1, a BS 110a may be a macro BS for a macro cell 102a, a BS 110b may be a pico BS for a pico cell 102b, and a BS 110c may be a femto BS for a femto cell 102c. A BS may support one or multiple (e.g., three) cells. The terms “eNB”, “base station”, ‘NR BS”, “gNB”, “TRP”, “AP”, “node B”, “5G NB”, and “cell” may be used interchangeably herein.

[0030] In some aspects, a cell may not necessarily be stationary, and the geographic area of the cell may move according to the location of a mobile BS. In some aspects, the BSs may be interconnected to one another and/or to one or more other BSs or network nodes (not shown) in the wireless network 100 through various types of backhaul interfaces, such as a direct physical connection or a virtual network, using any suitable transport network.

[0031] Wireless network 100 may also include relay stations. A relay station is an entity that can receive a transmission of data from an upstream station (e.g., a BS or a UE) and send a transmission of the data to a downstream station (e.g., a UE or a BS). A relay station may also be a UE that can relay transmissions for other UEs. In the example shown in Fig. 1, a relay BS 1 lOd may communicate with macro BS 110a and a UE 120d in order to facilitate communication between BS 110a and UE 120d. A relay BS may also be referred to as a relay station, a relay base station, a relay, or the like.

[0032] Wireless network 100 may be a heterogeneous network that includes BSs of different types, such as macro BSs, pico BSs, femto BSs, relay BSs, or the like. These different types of

BSs may have different transmit power levels, different coverage areas, and different impacts on interference in wireless network 100. For example, macro BSs may have a high transmit power level (e.g., 5 to 40 watts) whereas pico BSs, femto BSs, and relay BSs may have lower transmit power levels (e.g., 0.1 to 2 watts).

[0033] A network controller 130 may couple to a set of BSs and may provide coordination and control for these BSs. Network controller 130 may communicate with the BSs via a backhaul. The BSs may also communicate with one another, directly or indirectly, via a wireless or wireline backhaul.

[0034] UEs 120 (e.g., 120a, 120b, 120c) may be dispersed throughout wireless network 100, and each UE may be stationary or mobile. A UE may also be referred to as an access terminal, a terminal, a mobile station, a subscriber unit, a station, or the like. A UE may be a cellular phone (e.g., a smart phone), a personal digital assistant (PDA), a wireless modem, a wireless communication device, a handheld device, a laptop computer, a cordless phone, a wireless local loop (WLL) station, a tablet, a camera, a gaming device, a netbook, a smartbook, an ultrabook, a medical device or equipment, biometric sensors/devices, wearable devices (smart watches, smart clothing, smart glasses, smart wrist bands, smart jewelry (e.g., smart ring, smart bracelet)), an entertainment device (e.g., a music or video device, or a satellite radio), a vehicular component or sensor, smart meters/sensors, industrial manufacturing equipment, a global positioning system device, or any other suitable device that is configured to communicate via a wireless or wired medium.

[0035] Some UEs may be considered machine-type communication (MTC) or evolved or enhanced machine-type communication (eMTC) UEs. MTC and eMTC UEs include, for example, robots, drones, remote devices, sensors, meters, monitors, and/or location tags, that may communicate with abase station, another device (e.g., remote device), or some other entity. A wireless node may provide, for example, connectivity for or to a network (e.g., a wide area network such as Internet or a cellular network) via a wired or wireless communication link.

Some UEs may be considered Intemet-of-Things (IoT) devices, and/or may be implemented as NB-IoT (narrowband internet of things) devices. Some UEs may be considered a Customer Premises Equipment (CPE). UE 120 may be included inside a housing that houses components of UE 120, such as processor components and/or memory components. In some aspects, the processor components and the memory components may be coupled together. For example, the processor components (e.g., one or more processors) and the memory components (e.g., a memory) may be operatively coupled, communicatively coupled, electronically coupled, and/or electrically coupled.

[0036] In general, any number of wireless networks may be deployed in a given geographic area. Each wireless network may support a particular RAT and may operate on one or more frequencies. A RAT may also be referred to as a radio technology, an air interface, or the like.

A frequency may also be referred to as a carrier, a frequency channel, or the like. Each frequency may support a single RAT in a given geographic area in order to avoid interference between wireless networks of different RATs. In some cases, NR or 5G RAT networks may be deployed.

[0037] In some aspects, two or more UEs 120 (e.g., shown as UE 120a and UE 120e) may communicate directly using one or more sidelink channels (e.g., without using a base station 110 as an intermediary to communicate with one another). For example, the UEs 120 may communicate using peer-to-peer (P2P) communications, device-to-device (D2D) communications, a vehicle-to-everything (V2X) protocol (e.g., which may include a vehicle-to- vehicle (V2V) protocol or a vehicle-to-infrastructure (V2I) protocol), and/or a mesh network.

In this case, the UE 120 may perform scheduling operations, resource selection operations, and/or other operations described elsewhere herein as being performed by the base station 110. [0038] Devices of wireless network 100 may communicate using the electromagnetic spectrum, which may be subdivided based on frequency or wavelength into various classes, bands, channels, or the like. For example, devices of wireless network 100 may communicate using an operating band having a first frequency range (FR1), which may span from 410 MHz to 7.125 GHz, and/or may communicate using an operating band having a second frequency range (FR2), which may span from 24.25 GHz to 52.6 GHz. The frequencies between FR1 and FR2 are sometimes referred to as mid-band frequencies. Although a portion of FR1 is greater than 6 GHz, FR1 is often referred to as a “sub-6 GHz” band. Similarly, FR2 is often referred to as a “millimeter wave” band despite being different from the extremely high frequency (EHF) band (30 GHz - 300 GHz) which is identified by the International Telecommunications Union (ITU) as a “millimeter wave” band. Thus, unless specifically stated otherwise, it should be understood that the term “sub-6 GHz” or the like, if used herein, may broadly represent frequencies less than 6 GHz, frequencies within FR1, and/or mid-band frequencies (e.g., greater than 7.125 GHz). Similarly, unless specifically stated otherwise, it should be understood that the term “millimeter wave” or the like, if used herein, may broadly represent frequencies within the EHF band, frequencies within FR2, and/or mid-band frequencies (e.g., less than 24.25 GHz). It is contemplated that the frequencies included in FR1 and FR2 may be modified, and techniques described herein are applicable to those modified frequency ranges.

[0039] As indicated above, Fig. 1 is provided as an example. Other examples may differ from what is described with regard to Fig. 1.

[0040] Fig. 2 is a diagram illustrating an example 200 of a base station 110 in communication with a UE 120 in a wireless network 100, in accordance with the present disclosure. Base station 110 may be equipped with T antennas 234a through 234t, and UE 120 may be equipped with R antennas 252a through 252r, where in general T > 1 and R > 1.

[0041] At base station 110, a transmit processor 220 may receive data from a data source 212 for one or more UEs, select one or more modulation and coding schemes (MCS) for each UE based at least in part on channel quality indicators (CQIs) received from the UE, process (e.g., encode and modulate) the data for each UE based at least in part on the MCS(s) selected for the UE, and provide data symbols for all UEs. Transmit processor 220 may also process system information (e.g., for semi-static resource partitioning information (SRPI)) and control information (e.g., CQI requests, grants, and/or upper layer signaling) and provide overhead symbols and control symbols. Transmit processor 220 may also generate reference symbols for reference signals (e.g., a cell-specific reference signal (CRS) or a demodulation reference signal (DMRS)) and synchronization signals (e.g., a primary synchronization signal (PSS) or a secondary synchronization signal (SSS)). A transmit (TX) multiple-input multiple -output (MIMO) processor 230 may perform spatial processing (e.g., precoding) on the data symbols, the control symbols, the overhead symbols, and/or the reference symbols, if applicable, and may provide T output symbol streams to T modulators (MODs) 232a through 232t. Each modulator 232 may process a respective output symbol stream (e.g., for OFDM) to obtain an output sample stream. Each modulator 232 may further process (e.g., convert to analog, amplify, filter, and upconvert) the output sample stream to obtain a downlink signal. T downlink signals from modulators 232a through 232t may be transmitted via T antennas 234a through 234t, respectively.

[0042] At UE 120, antennas 252a through 252r may receive the downlink signals from base station 110 and/or other base stations and may provide received signals to demodulators (DEMODs) 254a through 254r, respectively. Each demodulator 254 may condition (e.g., filter, amplify, downconvert, and digitize) a received signal to obtain input samples. Each demodulator 254 may further process the input samples (e.g., for OFDM) to obtain received symbols. A MIMO detector 256 may obtain received symbols from all R demodulators 254a through 254r, perform MIMO detection on the received symbols if applicable, and provide detected symbols. A receive processor 258 may process (e.g., demodulate and decode) the detected symbols, provide decoded data for UE 120 to a data sink 260, and provide decoded control information and system information to a controller/processor 280. The term “controller/processor” may refer to one or more controllers, one or more processors, or a combination thereof. A channel processor may determine a reference signal received power (RSRP) parameter, a received signal strength indicator (RSSI) parameter, a reference signal received quality (RSRQ) parameter, and/or a channel quality indicator (CQI) parameter, among other examples. In some aspects, one or more components of UE 120 may be included in a housing 284.

[0043] Network controller 130 may include communication unit 294, controller/processor 290, and memory 292. Network controller 130 may include, for example, one or more devices in a core network. Network controller 130 may communicate with base station 110 via communication unit 294. [0044] Antennas (e.g., antennas 234a through 234t and/or antennas 252a through 252r) may include, or may be included within, one or more antenna panels, antenna groups, sets of antenna elements, and/or antenna arrays, among other examples. An antenna panel, an antenna group, a set of antenna elements, and/or an antenna array may include one or more antenna elements. An antenna panel, an antenna group, a set of antenna elements, and/or an antenna array may include a set of coplanar antenna elements and/or a set of non-coplanar antenna elements. An antenna panel, an antenna group, a set of antenna elements, and/or an antenna array may include antenna elements within a single housing and/or antenna elements within multiple housings. An antenna panel, an antenna group, a set of antenna elements, and/or an antenna array may include one or more antenna elements coupled to one or more transmission and/or reception components. [0045] On the uplink, at UE 120, a transmit processor 264 may receive and process data from a data source 262 and control information (e.g., for reports that include RSRP, RSSI, RSRQ, and/or CQI) from controller/processor 280. Transmit processor 264 may also generate reference symbols for one or more reference signals. The symbols from transmit processor 264 may be precoded by a TX MIMO processor 266 if applicable, further processed by modulators 254a through 254r (e.g., for DFT-s-OFDM or CP-OFDM), and transmitted to base station 110. In some aspects, a modulator and a demodulator (e.g., MOD/DEMOD 254) of the UE 120 may be included in a modem of the UE 120. In some aspects, the UE 120 includes a transceiver.

The transceiver may include any combination of antenna(s) 252, modulators and/or demodulators 254, MIMO detector 256, receive processor 258, transmit processor 264, and/or TX MIMO processor 266. The transceiver may be used by a processor (e.g., controller/processor 280) and memory 282 to perform aspects of any of the methods described herein (for example, as described with reference to Figs. 3-10).

[0046] At base station 110, the uplink signals from UE 120 and other UEs may be received by antennas 234, processed by demodulators 232, detected by a MIMO detector 236 if applicable, and further processed by a receive processor 238 to obtain decoded data and control information sent by UE 120. Receive processor 238 may provide the decoded data to a data sink 239 and the decoded control information to controller/processor 240. Base station 110 may include communication unit 244 and communicate to network controller 130 via communication unit 244. Base station 110 may include a scheduler 246 to schedule UEs 120 for downlink and/or uplink communications. In some aspects, a modulator and a demodulator (e.g., MOD/DEMOD 232) of the base station 110 may be included in a modem of the base station 110. In some aspects, the base station 110 includes a transceiver. The transceiver may include any combination of antenna(s) 234, modulators and/or demodulators 232, MIMO detector 236, receive processor 238, transmit processor 220, and/or TX MIMO processor 230. The transceiver may be used by a processor (e.g., controller/processor 240) and memory 242 to perform aspects of any of the methods described herein (for example, as described with reference to Figs. 3-10).

[0047] Controller/processor 240 of base station 110, controller/processor 280 of UE 120, and/or any other component(s) of Fig. 2 may perform one or more techniques associated with physical uplink control channel (PUCCH) resource indication for sidelink hybrid automatic repeat request (HARQ) feedback, as described in more detail elsewhere herein. For example, controller/processor 240 of base station 110, controller/processor 280 of UE 120, and/or any other com pone nt(s) of Fig. 2 may perform or direct operations of, for example, process 700 of Fig. 7, process 800 of Fig. 8, and/or other processes as described herein. Memories 242 and 282 may store data and program codes for base station 110 and UE 120, respectively. In some aspects, memory 242 and/or memory 282 may include a non-transitory computer-readable medium storing one or more instructions (e.g., code and/or program code) for wireless communication. For example, the one or more instructions, when executed (e.g., directly, or after compiling, converting, and/or interpreting) by one or more processors of the base station 110 and/or the UE 120, may cause the one or more processors, the UE 120, and/or the base station 110 to perform or direct operations of, for example, process 700 of Fig. 7, process 800 of Fig. 8, and/or other processes as described herein. In some aspects, executing instructions may include running the instructions, converting the instructions, compiling the instructions, and/or interpreting the instructions, among other examples.

[0048] In some aspects, a first UE 120 may include means for receiving an indication of a PUCCH resource for providing HARQ feedback for a sidelink data transmission from a second UE 120, means for transmitting the HARQ feedback for the sidelink data transmission on the PUCCH resource, and/or the like. In some aspects, such means may include one or more components of UE 120 described in connection with Fig. 2, such as controller/processor 280, transmit processor 264, TX MIMO processor 266, MOD 254, antenna 252, DEMOD 254, MIMO detector 256, receive processor 258, and/or the like.

[0049] In some aspects, base station 110 may include means for transmitting a downlink communication that includes an indication of a PUCCH resource for a first UE 120 to provide HARQ feedback for a sidelink data transmission from a second UE 120, means for receiving the HARQ feedback for the sidelink data transmission from the first UE on the PUCCH resource, and/or the like. In some aspects, such means may include one or more components of base station 110 described in connection with Fig. 2, such as antenna 234, DEMOD 232, MIMO detector 236, receive processor 238, controller/processor 240, transmit processor 220, TX MIMO processor 230, MOD 232, antenna 234, and/or the like.

[0050] While blocks in Fig. 2 are illustrated as distinct components, the functions described above with respect to the blocks may be implemented in a single hardware, software, or combination component or in various combinations of components. For example, the functions described with respect to the transmit processor 264, the receive processor 258, and/or the TX MIMO processor 266 may be performed by or under the control of controller/processor 280. [0051] As indicated above, Fig. 2 is provided as an example. Other examples may differ from what is described with regard to Fig. 2.

[0052] Fig. 3 is a diagram illustrating an example 300 of side link communications, in accordance with the present disclosure.

[0053] As shown in Fig. 3, a first UE 305-1 may communicate with a second UE 305-2 (and one or more other UEs 305) via one or more sidelink channels 310. The UEs 305-1 and 305-2 may communicate using the one or more sidelink channels 310 for P2P communications, D2D communications, V2X communications (e.g., which may include V2V communications, V2I communications, vehicle to person (V2P) communications, and/or the like), mesh networking, and/or the like. In some aspects, the UEs 305 (e.g., UE 305-1 and/or UE 305-2) may correspond to one or more other UEs described elsewhere herein, such as UE 120. In some aspects, the one or more sidelink channels 310 may use a PC5 interface, may operate in a high frequency band (e.g., the 5.9 GHz band), may operate on an unlicensed or shared frequency band (e.g., an NR unlicensed (NR-U) frequency band), and/or the like. Additionally, or alternatively, the UEs 305 may synchronize timing of transmission time intervals (TTIs) (e.g., frames, subframes, slots, symbols, and/or the like) using global navigation satellite system (GNSS) timing.

[0054] As further shown in Fig. 3, the one or more sidelink channels 310 may include a physical sidelink control channel (PSCCH) 315, a physical sidelink shared channel (PSSCH) 320, and/or a physical sidelink feedback channel (PSFCH) 325. The PSCCH 315 may be used to communicate control information, similar to a physical downlink control channel (PDCCH) and/or a PUCCH used for cellular communications with a base station 110 via an access link or an access channel. The PSSCH 320 may be used to communicate data, similar to a physical downlink shared channel (PDSCH) and/or a physical uplink shared channel (PUSCH) used for cellular communications with a base station 110 via an access link or an access channel.

[0055] The PSCCH 315 may carry sidelink control information part 1 (SCI-1) 330, which may indicate various control information used for sidelink communications. The control information may include an indication of one or more resources (e.g., time resources, frequency resources, spatial resources, and/or the like) where various types of information may be carried on the PSSCH 320, information for decoding sidelink communications on the PSSCH 320, a quality of service (QoS) priority value, a resource reservation period, a PSSCH demodulation reference signal (DMRS) pattern, a an SCI format and a beta offset for sidelink control information part 2 (SCI -2) 335 transmitted on the PSSCH 320, a quantity of PSSCH DMRS ports, a modulation coding scheme (MCS), and/or the like. [0056] The information carried on the PSSCH 320 may include the SCI-2335 and/or data 340. The SCI-2 335 may include various types of information, such as a HARQ process ID, a new data indicator (NDI) associated with the data 340, a source identifier, a destination identifier, a channel state information (CSI) report trigger, and/or the like. In some aspects, a UE 305 may transmit both the SCI-1 330 and the SCI-2335. In some aspects, a UE 305 may transmit only SCI-1 330, in which case one or more types of the information that would otherwise be transmitted in the SCI-2 335 may be transmitted in the SCI-1 330 instead.

[0057] The PSFCH 325 may be used to communicate sidelink feedback 345, such as HARQ feedback (e.g., acknowledgement or negative acknowledgement (ACK/NACK) information), transmit power control (TPC), a scheduling request (SR), and/or the like.

[0058] As indicated above, Fig. 3 is provided as an example. Other examples may differ from what is described with respect to Fig. 3.

[0059] Fig. 4 is a diagram illustrating an example 400 of sidelink communications and access link communications, in accordance with the present disclosure.

[0060] As shown in Fig. 4, a transmitter (Tx) UE 405 and a receiver (Rx) UE 410 may communicate with one another via a sidelink, as described above in connection with Fig. 3. As further shown, in some sidelink modes, a base station 110 may communicate with the Tx UE 405 via a first access link. Additionally, or alternatively, in some sidelink modes, the base station 110 may communicate with the Rx UE 410 via a second access link. The Tx UE 405 and/or the Rx UE 410 may correspond to one or more UEs described elsewhere herein, such as the UE 120 of Fig. 1. Thus, a direct link between UEs 120 (e.g., via a PC5 interface) may be referred to as a sidelink, and a direct link between a base station 110 and a UE 120 (e.g., via a Uu interface) may be referred to as an access link. Sidelink communications may be transmitted via the sidelink, and access link communications may be transmitted via the access link. An access link communication may be either a downlink communication (from a base station 110 to a UE 120) or an uplink communication (from a UE 120 to a base station 110).

[0061] In some aspects, the Tx UE 405 may operate in a resource allocation mode in which the base station 110 reserves and allocates sidelink resources for the Tx UE 405. This may be referred to as Mode 1 sidelink resource allocation. In some aspects, the Tx UE 405 may operate in a resource allocation mode in which sidelink resource selection and/or scheduling is performed by the Tx UE 405 (e.g., rather than the base station 110). This may be referred to as Mode 2 sidelink resource allocation.

[0062] In a Mode 2 sidelink resource allocation scheme, the base station 110 may transmit a sidelink grant to the Tx UE 405 via the access link. The sidelink grant may be a dynamic grant (e.g., received in a downlink control information (DCI) communication) or a semi- static/configured grant (e.g., received in a radio resource control (RRC) communication). For semi-static/configured grants, the base station 110 may activate a side link grant in the same RRC communication that configures the sidelink grant (referred to as a Type 1 configured grant) or may activate the sidelink grant in a DCI communication (referred to as a Type 2 configured grant).

[0063] As indicated above, Fig. 4 is provided as an example. Other examples may differ from what is described with respect to Fig. 4.

[0064] An Rx UE may be configured to provide, to a base station, feedback (e.g., HARQ feedback or another type of feedback) for a sidelink data transmission received from a Tx UE. The HARQ feedback may include an acknowledgement (ACK) for the sidelink data transmission or a negative acknowledgement (NACK) for the sidelink data transmission. The process for providing HARQ feedback to the base station may be a two-step process: the Rx UE transmits the HARQ feedback to the Tx UE on the sidelink, and the Tx UE relays the HARQ feedback to the base station on an access link. This two-step process may delay the HARQ feedback to the base station, which may delay the base station in scheduling a retransmission of the sidelink data transmission. Moreover, having the Tx UE relay the HARQ feedback to the base station increases the consumption of radio resources, processing resources, memory resources, and/or battery resources of the Tx UE.

[0065] Some aspects described herein provide techniques and apparatuses for PUCCH resource indication for sidelink HARQ feedback. In some aspects, a base station may provide an indication of a PUCCH resource to an Rx UE, and the Rx UE may use the PUCCH resource to transmit HARQ feedback to the base station for a sidelink data transmission received from a Tx UE. The base station may transmit the indication of the PUCCH resource directly to the Rx UE or may transmit the indication of the PUCCH resource to the Tx UE, and the Tx UE may forward the indication of the PUCCH resource to the Rx UE. In this way, the Rx UE may receive the indication of the PUCCH resource and may transmit the HARQ feedback for the sidelink data transmission directly to the base station (or through another base station, which may forward the HARQ feedback to the base station on a backhaul, if the Rx UE is served by a different base station from the Tx UE). This reduces delay in providing the HARQ feedback for the sidelink data transmission to the base station, which enables the base station to more quickly schedule a retransmission of the sidelink data transmission. Moreover, directly transmitting the HARQ feedback on the PUCCH resource reduces consumption of radio resources, processing resources, memory resources, and/or battery resources of the Tx UE because the Tx UE does not relay the HARQ feedback to the base station.

[0066] Fig. 5 is a diagram illustrating an example 500 associated with PUCCH resource indication for sidelink HARQ feedback, in accordance with the present disclosure. As shown in Fig. 5, example 500 may include access link communication between a base station 110 and a plurality of UEs (e.g., UEs 120), such as a Tx UE 505 and an Rx UE 510. The Tx UE 505 may be a UE that is to transmit sidelink data on a sidelink to the Rx UE 510, and the Rx UE 510 is a UE that is to receive the sidelink data on the sidelink.

[0067] As shown in Fig. 5, and by reference number 515, the base station 110 may transmit a sidelink transmit grant to the Tx UE 505. The sidelink transmit grant may be a grant or an allocation of sidelink resources for transmitting the sidelink data to the Rx UE 510 on the sidelink. For example, the sidelink transmit grant may indicate one or more frequency domain resources and/or one or more time domain resources for transmitting the sidelink data to the Rx UE 510 on a PSSCH.

[0068] In some aspects, the sidelink transmit grant may be transmitted according to Mode 1 sidelink resource allocation. In these cases, the Tx UE 505 may transmit an indication of a BSR to the base station 110, and the base station 110 may schedule or allocate the sidelink resources for transmission of the sidelink data based at least in part on the BSR. In some aspects, the sidelink transmit grant is a dynamic grant that is transmitted in a DCI communication. In some aspects, the sidelink transmit grant is a configured grant that is transmitted in an RRC communication, and activated by the RRC communication (e.g., a Type 1 configured grant) or activated by a DCI communication (e.g., a Type 2 configured grant).

[0069] In some aspects, if the base station 110 transmits the sidelink transmit grant to the Tx UE 505 in a DCI communication, the DCI communication may have a DCI format 3 0 communication or another DCI format for scheduling sidelink communications for one or more UEs. The sidelink transmit grant may include various parameters or fields for the Tx UE 505, the sidelink data, and/or for SCI-1 associated with the sidelink data. The parameters or fields may include, for example, a time gap relative to a first slot in a sidelink resource pool associated with the Tx UE 505 for the SCI-1, a HARQ process identifier associated with the DCI communication, a new data indicator associated with the sidelink data, an index of a subchannel allocation for the SCI-1, a frequency domain resource allocation (e.g., an allocation of frequency domain resources, such as one or more resource blocks, one or more resource elements, one or more subcarriers, one or more component carriers, and/or the like) associated with the SCI-1, a time domain resource allocation (e.g., an allocation of time domain resources, such as one or more symbols, one or more slots, one or more subframes, and/or the like) associated with the SCI-1, and/or the like.

[0070] As further shown in Fig. 5, and by reference number 520, the base station 110 may transmit a downlink communication to the Rx UE 510. The downlink communication may include an indication of a PUCCH resource on which the Rx UE 510 is to transmit HARQ feedback for the sidelink data transmission to the base station 110 (or to another base station

110 if the Tx UE 505 and the Rx UE 510 are served by different cells or base stations 110). The downlink communication may be an RRC communication, a medium access control control element (MAC-CE) communication, a DCI communication, or another type of downlink communication indicating the PUCCH resource. The PUCCH resource may include one or more time domain resources and/or one or more frequency domain resources on which the Rx UE 510 is to transmit the HARQ feedback on a PUCCH.

[0071] In some aspects, if the base station 110 transmits the indication of the PUCCH resource in an RRC communication or a MAC-CE communication, the base station 110 may transmit the RRC communication or the MAC-CE communication prior to transmitting the sidelink transmit grant at reference number 515 to the Tx UE 505. The RRC communication or the MAC-CE communication may semi-statically configure the PUCCH resource for the Rx UE 510.

[0072] In some aspects, if the base station 110 transmits the indication of the PUCCH resource in a DCI communication, the base station 110 may configure a sidelink receive grant in the DCI communication. The sidelink receive grant may indicate the PUCCH resource to the Rx UE 510. The sidelink receive grant may be an indication that another UE (e.g., Tx UE 505) is to transmit sidelink data to the Rx UE 510. In some aspects, the base station 110 may configure and transmit the sidelink receive grant to the Rx UE 510 based at least in part on receiving the BSR from the Tx UE 505. For example, the BSR may identify the Rx UE 510 as a destination of sidelink data that is to be transmitted by the Tx UE 505. Accordingly, the base station 110 may determine, based at least in part on an indication of the Rx UE 510 in the BSR, that Tx UE 505 is to transmit the sidelink data to the Rx UE 510, and may transmit the sidelink receive grant to the Rx UE 510 based at least in part on the determination.

[0073] In some aspects, the DCI communication may have a DCI format 3 0 communication or another DCI format for scheduling sidelink communications for one or more UEs. The base station 110 may configure the sidelink receive grant to include various parameters or fields (e.g., in addition to the indication of the PUCCH resource) for the Rx UE 510, the sidelink data, and/or for the SCI- 1 associated with the sidelink data. The parameters or fields may include, for example, a time gap relative to a first slot in a sidelink resource pool associated with the Tx UE 505 and the Rx UE 510 for the SCI-1, a HARQ process identifier associated with the DCI communication, a new data indicator associated with the sidelink data, an index of a subchannel allocation for the SCI-1, a frequency domain resource allocation associated with the SCI-1, a time domain resource allocation associated with the SCI-1, a PSSCH to HARQ feedback timing indication (e.g., an indication of a timing between a last symbol of the PSSCH carrying the sidelink data and providing HARQ feedback to the base station 110 for the DCI communication), a PUCCH resource indicator for the HARQ feedback, and/or the like. The sidelink receive grant may also include a sidelink transmission configuration indicator (TCI) state associated with the Rx UE 510 to indicate a beam configuration for the Rx UE 510.

[0074] As further shown in Fig. 5, and by reference number 525, the Tx UE 505 may transmit the sidelink data to the Rx UE 510. and the Rx UE 510 may receive the sidelink data transmission. To receive the sidelink data transmission, the Rx UE 510 may monitor the side link resources for the SCI-1, may receive the SCI-1 in the sidelink resources based at least in part on monitoring the sidelink resources, and may decode the SCI-1 based at least in part on receiving the SCI- 1. The Rx UE 510 may identify, in the SCI- 1 , information associated with SCI-2 and with the sidelink data to be transmitted to the Rx UE 510. The information may include, for example, an indication of PSSCH resources (e.g., time domain resources, frequency domain resources, and/or the like) in which the SCI-2 and/or the sidelink data is to be transmitted, an SCI format for the SCI-2, a beta offset for the SCI-2, and/or the like. The Rx UE 510 may monitor for and decode the SCI-2 based at least in part on the information included in the SCI-1 to determine which PSSCH is associated with the Rx UE 510 to receive the sidelink data transmission.

[0075] As further shown in Fig. 5, and by reference number 530, the Rx UE 510 may transmit HARQ feedback for the sidelink data transmission on the PUCCH resource indicated in the downlink transmission. In some aspects, if the Tx UE 505 and the Rx UE 510 are served by the same cell or base station 110, the Rx UE 510 may transmit the HARQ feedback directly to the base station 110 on the PUCCH resource (e.g., without relaying the HARQ feedback through Tx UE 505). In some aspects, if the Tx UE 505 and the Rx UE 510 are served by different cells or base stations 110, the Rx UE 510 may transmit the HARQ feedback to the base station 110 serving Rx UE 510 on the PUCCH resource (e.g., without relaying the HARQ feedback through Tx UE 505), the base station 110 serving Rx UE 510 may relay or forward the HARQ feedback, on a backhaul, to the base station 110 serving the Tx UE 505.

[0076] As further shown in Fig. 5, and by reference number 535, the Rx UE 510 may or may not (e.g., to conserve radio resources, processing resources, memory resources, and/or battery resources of the Rx UE 510) transmit the HARQ feedback to the Tx UE 505 on the sidelink. [0077] In this way, the base station 110 may transmit the indication of the PUCCH resource directly to the Rx UE 510 in a downlink transmission or may transmit the indication of the PUCCH resource to the Tx UE 505. In this way, the Rx UE 510 may receive the indication of the PUCCH resource and may transmit the HARQ feedback for the sidelink data transmission directly to the base station (or through another base station 110, which may forward the HARQ feedback to the base station 110 on a backhaul, if the Rx UE 510 is served by a different base station 110 from the Tx UE 505). This reduces delay in providing the HARQ feedback for the sidelink data transmission to the base station 110, which enables the base station 110 to more quickly schedule a retransmission of the sidelink data transmission, if necessary. Moreover, directly transmitting the HARQ feedback on the PUCCH resource reduces consumption of radio resources, processing resources, memory resources, and/or battery resources of the Tx UE 505 because the Tx UE 505 does not relay the HARQ feedback to the base station 110. [0078] As indicated above, Fig. 5 is provided as an example. Other examples may differ from what is described with respect to Fig. 5.

[0079] Fig. 6 is a diagram illustrating an example 600 associated with a receive grant for a sidelink transmission, in accordance with the present disclosure. As shown in Fig. 6, example 600 may include access link communication between a base station 110 and a plurality of UEs (e.g., UEs 120), such as a Tx UE 605 and an Rx UE 610. The Tx UE 605 may be a UE that is to transmit sidelink data on a sidelink to the Rx UE 610, and the Rx UE 610 is a UE that is to receive the sidelink data on the sidelink.

[0080] As shown in Fig. 6, and by reference number 615, the base station 110 may transmit a sidelink transmit grant to the Tx UE 605. The sidelink transmit grant may be a grant or an allocation of sidelink resources for transmitting the sidelink data to the Rx UE 610 on the sidelink. For example, the sidelink transmit grant may indicate one or more frequency domain resources and/or one or more time domain resources for transmitting the sidelink data to the Rx UE 610 on a PSSCH.

[0081] In some aspects, the sidelink transmit grant may be transmitted according to Mode 1 sidelink resource allocation. In these cases, the Tx UE 605 may transmit an indication of a buffer status report (BSR) to the base station 110, and the base station 110 may schedule or allocate the sidelink resources for transmission of the sidelink data based at least in part on the BSR. In some aspects, the sidelink transmit grant is a dynamic grant that is transmitted in a DCI communication. In some aspects, the sidelink transmit grant is a configured grant that is transmitted in an RRC communication, and activated by the RRC communication (e.g., a Type 1 configured grant) or activated by a DCI communication (e.g., a Type 2 configured grant). [0082] In some aspects, if the base station 110 transmits the sidelink transmit grant to the Tx UE 605 in a DCI communication, the DCI communication may have a DCI format 3 0 communication or another DCI format for scheduling sidelink communications for one or more UEs. The sidelink transmit grant may include various parameters or fields for the Tx UE 605, the sidelink data, and/or for SCI-1 associated with the sidelink data. The parameters or fields may include, for example, a time gap relative to a first slot in a sidelink resource pool associated with the Tx UE 605 for the SCI-1, a HARQ process identifier associated with the DCI communication, a new data indicator associated with the sidelink data, an index of a subchannel allocation for the SCI-1, a frequency domain resource allocation (e.g., an allocation of frequency domain resources, such as one or more resource blocks, one or more resource elements, one or more subcarriers, one or more component carriers, and/or the like) associated with the SCI-1, a time domain resource allocation (e.g., an allocation of time domain resources, such as one or more symbols, one or more slots, one or more subframes, and/or the like) associated with the SCI-1, and/or the like. The sidelink transmit grant (or the DCI communication carrying the sidelink transmit grant) may further include an indication of a PUCCH resource on which the Rx UE 610 is to transmit HARQ feedback for the sidelink data transmission to the base station 110 (or to another base station 110 if the Tx UE 505 and the Rx UE 510 are served by different cells or base stations 110).

[0083] As further shown in Fig. 6, and by reference number 620, the Tx UE 605 may transmit SCI-1 and SCI-2 to the Rx UE 510. The SCI-1 and SCI-2 may be associated with (and may indicate) that the Tx UE 605 is to transmit the sidelink data to the Rx UE 610. The SCI-1 and/or SCI-2 may further include an indication of the PUCCH resource on which the Rx UE 510 is to transmit HARQ feedback for the sidelink data to the base station 110 (or to another base station 110 if the Tx UE 505 and the Rx UE 510 are served by different cells or base stations 110).

[0084] As further shown in Fig. 6, and by reference number 625, the Tx UE 505 may transmit the sidelink data to the Rx UE 610, and the Rx UE 610 may receive the sidelink data transmission. To receive the sidelink data transmission, the Rx UE 610 may monitor the sidelink resources for the SCI-1, may receive the SCI-1 in the sidelink resources based at least in part on monitoring the sidelink resources, and may decode the SCI-1 based at least in part on receiving the SCI-1. The Rx UE 610 may identify, in the SCI-1, information associated with SCI-2 and with the sidelink data to be transmitted to the Rx UE 610. The information may include, for example, an indication of PSSCH resources (e.g., time domain resources, frequency domain resources, and/or the like) in which the SCI-2 and/or the sidelink data is to be transmitted, an SCI format for the SCI-2, a beta offset for the SCI-2, and/or the like. The Rx UE 610 may monitor for and decode the SCI-2 based at least in part on the information included in the SCI-1 to determine which PSSCH is associated with the Rx UE 510 to receive the sidelink data transmission. The Rx UE 610 may further identify the PUCCH resource indicated by the SCI-1, the SCI-2, or a combination thereof.

[0085] As further shown in Fig. 6, and by reference number 630, the Rx UE 610 may transmit HARQ feedback for the sidelink data transmission on the PUCCH resource indicated in the downlink transmission. In some aspects, if the Tx UE 605 and the Rx UE 610 are served by the same cell or base station 110, the Rx UE 610 may transmit the HARQ feedback directly to the base station 110 on the PUCCH resource (e.g., without relaying the HARQ feedback through Tx UE 605). In some aspects, if the Tx UE 605 and the Rx UE 610 are served by different cells or base stations 110, the Rx UE 610 may transmit the HARQ feedback to the base station 110 serving Rx UE 510 on the PUCCH resource (e.g., without relaying the HARQ feedback through Tx UE 605), the base station 110 serving Rx UE 610 may relay or forward the HARQ feedback to the base station 110 serving the Tx UE 605 on a backhaul. [0086] As further shown in Fig. 6, and by reference number 635, the Rx UE 610 may or may not (e.g., to conserve radio resources, processing resources, memory resources, and/or battery resources of the Rx UE 610) transmit the HARQ feedback to the Tx UE 605 on the sidelink. [0087] In this way, the base station 110 may transmit the indication of the PUCCH resource to the Tx UE 605, and the Tx UE 605 may forward the indication of the PUCCH resource to the Rx UE 610. In this way, the Rx UE 610 may receive the indication of the PUCCH resource and may transmit the HARQ feedback for the sidelink data transmission directly to the base station 110 (or through another base station 110, which may forward the HARQ feedback to the base station 110 on a backhaul, if the Rx UE 610 is served by a different base station 110 from the Tx UE 605). This reduces delay in providing the HARQ feedback for the sidelink data transmission to the base station 110, which enables the base station 110 to more quickly schedule a retransmission of the sidelink data transmission. Moreover, directly transmitting the HARQ feedback on the PUCCH resource reduces consumption of radio resources, processing resources, memory resources, and/or battery resources of the Tx UE 605 because the Tx UE 605 does not relay the HARQ feedback to the base station 110.

[0088] As indicated above, Fig. 6 is provided as an example. Other examples may differ from what is described with respect to Fig. 6.

[0089] Fig. 7 is a diagram illustrating an example process 700 performed, for example, by a first UE, in accordance with the present disclosure. Example process 700 is an example where the first UE (e.g., UE 120, UE 305, Rx UE 410, Rx UE 510, Rx UE 610, and/or the like) performs operations associated with PUCCH resource indication for sidelink HARQ feedback. [0090] As shown in Fig. 7, in some aspects, process 700 may include receiving an indication of a PUCCH resource for providing HARQ feedback for a sidelink data transmission from a second UE (block 710). For example, the UE (e.g., using receive processor 258, transmit processor 264, controller/processor 280, memory 282, and/or the like) may receive an indication of a PUCCH resource for providing HARQ feedback for a sidelink data transmission from a second UE, as described above.

[0091] As further shown in Fig. 7, in some aspects, process 700 may include transmitting the HARQ feedback for the sidelink data transmission on the PUCCH resource (block 720). For example, the UE (e.g., using receive processor 258, transmit processor 264, controller/processor 280, memory 282, and/or the like) may transmit the HARQ feedback for the sidelink data transmission on the PUCCH resource, as described above.

[0092] Process 700 may include additional aspects, such as any single aspect or any combination of aspects described below and/or in connection with one or more other processes described elsewhere herein. [0093] In a first aspect, process 700 includes transmitting a copy of the HARQ feedback on a PSFCH to the second UE. In a second aspect, alone or in combination with the first aspect, process 700 includes refraining from transmitting a copy of the HARQ feedback on a PSFCH to the second UE. In a third aspect, alone or in combination with one or more of the first and second aspects, receiving the indication of the PUCCH resource comprises receiving, from a base station, a DCI communication that includes a sidelink receive grant for the first UE, wherein the sidelink receive grant includes the indication of the PUCCH resource and an indication that the second UE is to transmit the sidelink data transmission to the first UE.

[0094] In a fourth aspect, alone or in combination with one or more of the first through third aspects, the DCI communication is a DCI format 3 0 communication. In a fifth aspect, alone or in combination with one or more of the first through fourth aspects, receiving the indication of the PUCCH resource comprises receiving, from a base station, a downlink communication that includes the indication of the PUCCH resource, wherein the downlink communication is an RRC communication or a MAC-CE communication. In a sixth aspect, alone or in combination with one or more of the first through fifth aspects, receiving the indication of the PUCCH resource comprises receiving, from the second UE, an SCI communication, associated with the sidelink data transmission, that includes the indication of the PUCCH resource.

[0095] In a seventh aspect, alone or in combination with one or more of the first through sixth aspects, transmitting the HARQ feedback on the PUCCH resource comprises transmitting the HARQ feedback on the PUCCH resource to a base station associated with the first UE and the second UE. In an eighth aspect, alone or in combination with one or more of the first through seventh aspects, transmitting the HARQ feedback on the PUCCH resource comprises transmitting the HARQ feedback on the PUCCH resource to a first base station associated with the first UE, the HARQ feedback is for a second base station associated with the second UE, and the first base station and the second base station are different base stations.

[0096] Although Fig. 7 shows example blocks of process 700, in some aspects, process 700 may include additional blocks, fewer blocks, different blocks, or differently arranged blocks than those depicted in Fig. 7. Additionally, or alternatively, two or more of the blocks of process 700 may be performed in parallel.

[0097] Fig. 8 is a diagram illustrating an example process 800 performed, for example, by a base station, in accordance with the present disclosure. Example process 800 is an example where the base station (e.g., base station 110 and/or the like) performs operations associated with PUCCH resource indication for sidelink HARQ feedback.

[0098] As shown in Fig. 8, in some aspects, process 800 may include transmitting a downlink communication that includes an indication of a PUCCH resource for a first UE to provide HARQ feedback for a sidelink data transmission from a second UE (block 810). For example, the base station (e.g., using transmit processor 220, receive processor 238, controller/processor 240, memory 242, and/or the like) may transmit a downlink communication that includes an indication of a PUCCH resource for a first UE to provide HARQ feedback for a sidelink data transmission from a second UE, as described above.

[0099] As further shown in Fig. 8, in some aspects, process 800 may include receiving the HARQ feedback for the sidelink data transmission from the first UE on the PUCCH resource (block 820). For example, the base station (e.g., using transmit processor 220, receive processor 238, controller/processor 240, memory 242, and/or the like) may receive the HARQ feedback for the sidelink data transmission from the first UE on the PUCCH resource, as described above. [0100] Process 800 may include additional aspects, such as any single aspect or any combination of aspects described below and/or in connection with one or more other processes described elsewhere herein.

[0101] In a first aspect, transmitting the indication of the PUCCH resource comprises transmitting, to the first UE, a DCI communication that includes a sidelink receive grant for the first UE, wherein the sidelink receive grant includes the indication of the PUCCH resource and an indication that the second UE is to transmit the sidelink data transmission to the first UE. In a second aspect, alone or in combination with the first aspect, the DCI communication is a DCI format 3 0 communication.

[0102] In a third aspect, alone or in combination with one or more of the first and second aspects, transmitting the indication of the PUCCH resource comprises transmitting, to the first UE, the downlink communication that includes the indication of the PUCCH resource, wherein the downlink communication is an RRC communication or a MAC-CE communication. In a fourth aspect, alone or in combination with one or more of the first through third aspects, transmitting the indication of the PUCCH resource comprises transmitting, to the second UE, a DCI communication that includes a sidelink transmit grant, associated with the sidelink data transmission, for the second UE, wherein the sidelink transmit grant includes the indication of the PUCCH resource.

[0103] Although Fig. 8 shows example blocks of process 800, in some aspects, process 800 may include additional blocks, fewer blocks, different blocks, or differently arranged blocks than those depicted in Fig. 8. Additionally, or alternatively, two or more of the blocks of process 800 may be performed in parallel.

[0104] Fig. 9 is a block diagram of an example apparatus 900 for wireless communication. The apparatus 900 may be a UE (e.g., UE 120, UE 305, Rx UE 410, Rx UE 510, Rx UE 610, and/or the like), or a UE may include the apparatus 900. In some aspects, the apparatus 900 includes a reception component 902 and a transmission component 904, which may be in communication with one another (for example, via one or more buses and/or one or more other components). As shown, the apparatus 900 may communicate with one or more other apparatuses 906 and 908 (such as a UE, a base station, or another wireless communication device) using the reception component 902 and the transmission component 904.

[0105] In some aspects, the apparatus 900 may be configured to perform one or more operations described herein in connection with Figs. 3-6. Additionally or alternatively, the apparatus 900 may be configured to perform one or more processes described herein, such as process 700 of Fig. 7. In some aspects, the apparatus 900 and/or one or more components shown in Fig. 9 may include one or more components of the UE described above in connection with Fig. 2. Additionally, or alternatively, one or more components shown in Fig. 9 may be implemented within one or more components described above in connection with Fig. 2. Additionally or alternatively, one or more components of the set of components may be implemented at least in part as software stored in a memory. For example, a component (or a portion of a component) may be implemented as instructions or code stored in a non-transitory computer-readable medium and executable by a controller or a processor to perform the functions or operations of the component.

[0106] The reception component 902 may receive communications, such as reference signals, control information, data communications, or a combination thereof, from the apparatus 906 and/or the apparatus 908. The reception component 902 may provide received communications to one or more other components of the apparatus 900. In some aspects, the reception component 902 may perform signal processing on the received communications (such as filtering, amplification, demodulation, analog-to-digital conversion, demultiplexing, deinterleaving, de-mapping, equalization, interference cancellation, or decoding, among other examples), and may provide the processed signals to the one or more other components of the apparatus 906 and/or the apparatus 908. In some aspects, the reception component 902 may include one or more antennas, a demodulator, a MIMO detector, a receive processor, a controller/processor, a memory, or a combination thereof, of the UE described above in connection with Fig. 2.

[0107] The transmission component 904 may transmit communications, such as reference signals, control information, data communications, or a combination thereof, to the apparatus 906 and/or the apparatus 908. In some aspects, one or more other components of the apparatus 906 and/or the apparatus 908 may generate communications and may provide the generated communications to the transmission component 904 for transmission to the apparatus 906 and/or the apparatus 908. In some aspects, the transmission component 904 may perform signal processing on the generated communications (such as filtering, amplification, modulation, digital-to-analog conversion, multiplexing, interleaving, mapping, or encoding, among other examples), and may transmit the processed signals to the apparatus 906 and/or the apparatus

908. In some aspects, the transmission component 904 may include one or more antennas, a modulator, a transmit MIMO processor, a transmit processor, a controller/processor, a memory, or a combination thereof, of the UE described above in connection with Fig. 2. In some aspects, the transmission component 904 may be co-located with the reception component 902 in a transceiver.

[0108] The reception component 902 may receive an indication of a PUCCH resource for providing HARQ feedback for a sidelink data transmission from the apparatus 908. In some aspects, the reception component 902 may receive the indication of a PUCCH resource from the apparatus 906 or the apparatus 908. The reception component 902 may receive the sidelink data transmission from the apparatus 908. The transmission component 904 may transmit the HARQ feedback for the sidelink data transmission on the PUCCH resource. In some aspects, the transmission component 904 may transmit the HARQ feedback directly to the apparatus 906 or to the apparatus 906 through another apparatus that forwards or relays the HARQ feedback on a backhaul.

[0109] The number and arrangement of components shown in Fig. 9 are provided as an example. In practice, there may be additional components, fewer components, different components, or differently arranged components than those shown in Fig. 9. Furthermore, two or more components shown in Fig. 9 may be implemented within a single component, or a single component shown in Fig. 9 may be implemented as multiple, distributed components. Additionally or alternatively, a set of (one or more) components shown in Fig. 9 may perform one or more functions described as being performed by another set of components shown in Fig. 9.

[0110] Fig. 10 is a block diagram of an example apparatus 1000 for wireless communication. The apparatus 1000 may be a base station (e.g., a base station 110), or a base station may include the apparatus 1000. In some aspects, the apparatus 1000 includes a reception component 1002 and a transmission component 1004, which may be in communication with one another (for example, via one or more buses and/or one or more other components). As shown, the apparatus 1000 may communicate with other apparatuses 1006 and 1008 (such as a UE, a base station, or another wireless communication device) using the reception component 1002 and the transmission component 1004.

[0111] In some aspects, the apparatus 1000 may be configured to perform one or more operations described herein in connection with Figs. 3-6. Additionally or alternatively, the apparatus 1000 may be configured to perform one or more processes described herein, such as process 800 of Fig. 8. In some aspects, the apparatus 1000 and/or one or more components shown in Fig. 10 may include one or more components of the base station described above in connection with Fig. 2. Additionally, or alternatively, one or more components shown in Fig.

10 may be implemented within one or more components described above in connection with

Fig. 2. Additionally or alternatively, one or more components of the set of components may be implemented at least in part as software stored in a memory. For example, a component (or a portion of a component) may be implemented as instructions or code stored in a non-transitory computer-readable medium and executable by a controller or a processor to perform the functions or operations of the component.

[0112] The reception component 1002 may receive communications, such as reference signals, control information, data communications, or a combination thereof, from the apparatus 1006 and/or the apparatus 1008. The reception component 1002 may provide received communications to one or more other components of the apparatus 1000. In some aspects, the reception component 1002 may perform signal processing on the received communications (such as filtering, amplification, demodulation, analog-to-digital conversion, demultiplexing, deinterleaving, de-mapping, equalization, interference cancellation, or decoding, among other examples), and may provide the processed signals to the one or more other components of the apparatus 1006 and/or the apparatus 1008. In some aspects, the reception component 1002 may include one or more antennas, a demodulator, a MIMO detector, a receive processor, a controller/processor, a memory, or a combination thereof, of the base station described above in connection with Fig. 2.

[0113] The transmission component 1004 may transmit communications, such as reference signals, control information, data communications, or a combination thereof, to the apparatus 1006 and/or the apparatus 1008. In some aspects, one or more other components of the apparatus 1006 and/or the apparatus 1008 may generate communications and may provide the generated communications to the transmission component 1004 for transmission to the apparatus 1006 and/or the apparatus 1008. In some aspects, the transmission component 1004 may perform signal processing on the generated communications (such as filtering, amplification, modulation, digital-to-analog conversion, multiplexing, interleaving, mapping, or encoding, among other examples), and may transmit the processed signals to the apparatus 1006 and/or the apparatus 1008. In some aspects, the transmission component 1004 may include one or more antennas, a modulator, a transmit MIMO processor, a transmit processor, a controller/processor, a memory, or a combination thereof, of the base station described above in connection with Fig. 2. In some aspects, the transmission component 1004 may be co-located with the reception component 1002 in a transceiver.

[0114] The transmission component 1004 may transmit a downlink communication that includes an indication of a PUCCH resource for the apparatus 1008 to provide HARQ feedback for a sidelink data transmission to the apparatus 1008 from the apparatus 1006. In some aspects, the transmission component 1004 may transmit the downlink communication to the apparatus 1008. In some aspects, the transmission component 1004 may transmit the downlink communication to the apparatus 1006, and the apparatus 1006 may transmit the indication of the

PUCCH resource to the apparatus 1008 (e.g., in SCI-1 and/or SCI-2). The reception component 1002 may receive the HARQ feedback for the sidelink data transmission on the PUCCH resource. In some aspects, the reception component 1002 may receive the HARQ feedback for the sidelink data transmission directly from the apparatus 1008 on the PUCCH resource. In some aspects, the apparatus 1008 may transmit the HARQ feedback to another apparatus on the PUCCH resource, and the other apparatus may transmit the HARQ feedback to the reception component 1002 on a backhaul.

[0115] The number and arrangement of components shown in Fig. 10 are provided as an example. In practice, there may be additional components, fewer components, different components, or differently arranged components than those shown in Fig. 10. Furthermore, two or more components shown in Fig. 10 may be implemented within a single component, or a single component shown in Fig. 10 may be implemented as multiple, distributed components. Additionally or alternatively, a set of (one or more) components shown in Fig. 10 may perform one or more functions described as being performed by another set of components shown in Fig. 10

[0116] The following provides an overview of some Aspects of the present disclosure:

[0117] Aspect 1 : A method of wireless communication performed by a first user equipment (UE), comprising: receiving an indication of a physical uplink control channel (PUCCH) resource for providing hybrid automatic repeat request (HARQ) feedback for a sidelink data transmission from a second UE; and transmitting the HARQ feedback for the sidelink data transmission on the PUCCH resource.

[0118] Aspect 2: The method of Aspect 1, further comprising: transmitting a copy of the HARQ feedback on a physical sidelink feedback channel (PSFCH) to the second UE. Aspect 3: The method of Aspect 1 or 2, further comprising: refraining from transmitting a copy of the HARQ feedback on a physical sidelink feedback channel (PSFCH) to the second UE.

[0119] Aspect 4: The method of any of Aspects 1-3, wherein receiving the indication of the PUCCH resource comprises: receiving, from a base station, a downlink control information (DCI) communication that includes a sidelink receive grant for the first UE, wherein the sidelink receive grant includes the indication of the PUCCH resource and an indication that the second UE is to transmit the sidelink data transmission to the first UE. Aspect 5: The method of Aspect 4, wherein the DCI communication is a DCI format 3 0 communication.

[0120] Aspect 6: The method of any of Aspects 1-3, wherein receiving the indication of the PUCCH resource comprises: receiving, from a base station, a downlink communication that includes the indication of the PUCCH resource, wherein the downlink communication is a radio resource control (RRC) communication or a medium access control control element (MAC-CE) communication. Aspect 7: The method of any of Aspects 1-3, wherein receiving the indication of the PUCCH resource comprises: receiving, from the second UE, a sidelink control information (SCI) communication, associated with the sidelink data transmission, that includes the indication of the PUCCH resource.

[0121] Aspect 8: The method of any of Aspects 1-7, wherein transmitting the HARQ feedback on the PUCCH resource comprises: transmitting the HARQ feedback on the PUCCH resource to a base station associated with the first UE and the second UE. Aspect 9: The method of any of Aspects 1-7, wherein transmitting the HARQ feedback on the PUCCH resource comprises: transmitting the HARQ feedback on the PUCCH resource to a first base station associated with the first UE, wherein the HARQ feedback is for a second base station associated with the second UE, and wherein the first base station and the second base station are different base stations.

[0122] Aspect 10: A method of wireless communication performed by a base station, comprising: transmitting a downlink communication that includes an indication of a physical uplink control channel (PUCCH) resource for a first user equipment (UE) to provide hybrid automatic repeat request (HARQ) feedback for a sidelink data transmission from a second UE; and receiving the HARQ feedback for the sidelink data transmission from the first UE on the PUCCH resource.

[0123] Aspect 11 : The method of Aspect 10, wherein transmitting the indication of the PUCCH resource comprises: transmitting, to the first UE, a downlink control information (DCI) communication that includes a sidelink receive grant for the first UE, wherein the sidelink receive grant includes the indication of the PUCCH resource and an indication that the second UE is to transmit the sidelink data transmission to the first UE.

[0124] Aspect 12: The method of Aspect 10 or 11, wherein the DCI communication is a DCI format 3_0 communication. Aspect 13: The method of any of Aspects 10-12, wherein transmitting the indication of the PUCCH resource comprises: transmitting, to the first UE, the downlink communication that includes the indication of the PUCCH resource, wherein the downlink communication is a radio resource control (RRC) communication or a medium access control control element (MAC-CE) communication.

[0125] Aspect 14: The method of any of Aspects 10-13, wherein transmitting the indication of the PUCCH resource comprises: transmitting, to the second UE, a downlink control information (DCI) communication that includes a sidelink transmit grant, associated with the sidelink data transmission, for the second UE, wherein the sidelink transmit grant includes the indication of the PUCCH resource.

[0126] Aspect 15: An apparatus for wireless communication at a device, comprising a processor; memory coupled with the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform the method of one or more of Aspects 1-9. Aspect 16: A device for wireless communication, comprising a memory and one or more processors coupled to the memory, the one or more processors configured to perform the method of one or more of Aspects 1-9. Aspect 17: An apparatus for wireless communication, comprising at least one means for performing the method of one or more of Aspects 1-9.

[0127] Aspect 18: A non-transitory computer-readable medium storing code for wireless communication, the code comprising instructions executable by a processor to perform the method of one or more of Aspects 1-9. Aspect 19: A non-transitory computer-readable medium storing a set of instructions for wireless communication, the set of instructions comprising one or more instructions that, when executed by one or more processors of a device, cause the device to perform the method of one or more of Aspects 1-9.

[0128] Aspect 20: An apparatus for wireless communication at a device, comprising a processor; memory coupled with the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform the method of one or more of Aspects 10-14. Aspect 21: A device for wireless communication, comprising a memory and one or more processors coupled to the memory, the one or more processors configured to perform the method of one or more of Aspects 10-14. Aspect 22: An apparatus for wireless communication, comprising at least one means for performing the method of one or more of Aspects 10-14.

[0129] Aspect 23: A non-transitory computer-readable medium storing code for wireless communication, the code comprising instructions executable by a processor to perform the method of one or more of Aspects 10-14. Aspect 24: A non-transitory computer-readable medium storing a set of instructions for wireless communication, the set of instructions comprising one or more instructions that, when executed by one or more processors of a device, cause the device to perform the method of one or more of Aspects 10-14.

[0130] The foregoing disclosure provides illustration and description, but is not intended to be exhaustive or to limit the aspects to the precise forms disclosed. Modifications and variations may be made in light of the above disclosure or may be acquired from practice of the aspects.

[0131] As used herein, the term “component” is intended to be broadly construed as hardware and/or a combination of hardware and software. “Software” shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, and/or functions, among other examples, whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise. As used herein, a processor is implemented in hardware and/or a combination of hardware and software. It will be apparent that systems and/or methods described herein may be implemented in different forms of hardware and/or a combination of hardware and software. The actual specialized control hardware or software code used to implement these systems and/or methods is not limiting of the aspects. Thus, the operation and behavior of the systems and/or methods were described herein without reference to specific software code — it being understood that software and hardware can be designed to implement the systems and/or methods based, at least in part, on the description herein.

[0132] As used herein, satisfying a threshold may, depending on the context, refer to a value being greater than the threshold, greater than or equal to the threshold, less than the threshold, less than or equal to the threshold, equal to the threshold, not equal to the threshold, or the like. [0133] Even though particular combinations of features are recited in the claims and/or disclosed in the specification, these combinations are not intended to limit the disclosure of various aspects. In fact, many of these features may be combined in ways not specifically recited in the claims and/or disclosed in the specification. Although each dependent claim listed below may directly depend on only one claim, the disclosure of various aspects includes each dependent claim in combination with every other claim in the claim set. As used herein, a phrase referring to “at least one of’ a list of items refers to any combination of those items, including single members. As an example, “at least one of: a, b, or c” is intended to cover a, b, c, a-b, a-c, b-c, and a-b-c, as well as any combination with multiples of the same element (e.g., a-a, a-a-a, a-a-b, a-a-c, a-b-b, a-c-c, b-b, b-b-b, b-b-c, c-c, and c-c-c or any other ordering of a, b, and c).

[0134] No element, act, or instruction used herein should be construed as critical or essential unless explicitly described as such. Also, as used herein, the articles “a” and “an” are intended to include one or more items and may be used interchangeably with “one or more.” Further, as used herein, the article “the” is intended to include one or more items referenced in connection with the article “the” and may be used interchangeably with “the one or more.” Furthermore, as used herein, the terms “set” and “group” are intended to include one or more items (e.g., related items, unrelated items, or a combination of related and unrelated items), and may be used interchangeably with “one or more.” Where only one item is intended, the phrase “only one” or similar language is used. Also, as used herein, the terms “has,” “have,” “having,” or the like are intended to be open-ended terms. Further, the phrase “based on” is intended to mean “based, at least in part, on” unless explicitly stated otherwise. Also, as used herein, the term “or” is intended to be inclusive when used in a series and may be used interchangeably with “and/or,” unless explicitly stated otherwise (e.g., if used in combination with “either” or “only one of’).

Claims

WHAT IS CLAIMED IS:

1. A method of wireless communication performed by a first user equipment (UE), comprising: receiving an indication of a physical uplink control channel (PUCCH) resource for providing hybrid automatic repeat request (HARQ) feedback for a sidelink data transmission from a second UE; and transmitting the HARQ feedback for the sidelink data transmission on the PUCCH resource.

2. The method of claim 1, further comprising: transmitting a copy of the HARQ feedback on a physical sidelink feedback channel (PSFCH) to the second UE.

3. The method of claim 1, further comprising: refraining from transmitting a copy of the HARQ feedback on a physical sidelink feedback channel (PSFCH) to the second UE.

4. The method of claim 1, wherein receiving the indication of the PUCCH resource comprises: receiving, from a base station, a downlink control information (DCI) communication that includes a sidelink receive grant for the first UE, wherein the sidelink receive grant includes the indication of the PUCCH resource and an indication that the second UE is to transmit the sidelink data transmission to the first UE.

5. The method of claim 4, wherein the DCI communication is a DCI format 3 0 communication.

6. The method of claim 1, wherein receiving the indication of the PUCCH resource comprises: receiving, from a base station, a downlink communication that includes the indication of the PUCCH resource, wherein the downlink communication is a radio resource control (RRC) communication or a medium access control control element (MAC-CE) communication.

7. The method of claim 1, wherein receiving the indication of the PUCCH resource comprises: receiving, from the second UE, a sidelink control information (SCI) communication, associated with the sidelink data transmission, that includes the indication of the PUCCH resource.

8. The method of claim 1, wherein transmitting the HARQ feedback on the PUCCH resource comprises: transmitting the HARQ feedback on the PUCCH resource to a base station associated with the first UE and the second UE.

9. The method of claim 1, wherein transmitting the HARQ feedback on the PUCCH resource comprises: transmitting the HARQ feedback on the PUCCH resource to a first base station associated with the first UE, wherein the HARQ feedback is for a second base station associated with the second UE, and wherein the first base station and the second base station are different base stations.

10. A method of wireless communication performed by a base station, comprising: transmitting a downlink communication that includes an indication of a physical uplink control channel (PUCCH) resource for a first user equipment (UE) to provide hybrid automatic repeat request (HARQ) feedback for a sidelink data transmission from a second UE; and receiving the HARQ feedback for the sidelink data transmission from the first UE on the PUCCH resource.

11. The method of claim 10, wherein transmitting the indication of the PUCCH resource comprises: transmitting, to the first UE, a downlink control information (DCI) communication that includes a sidelink receive grant for the first UE, wherein the sidelink receive grant includes the indication of the PUCCH resource and an indication that the second UE is to transmit the sidelink data transmission to the first UE.

12. The method of claim 11, wherein the DCI communication is a DCI format 3 0 communication.

13. The method of claim 10, wherein transmitting the indication of the PUCCH resource comprises: transmitting, to the first UE, the downlink communication that includes the indication of the PUCCH resource, wherein the downlink communication is a radio resource control (RRC) communication or a medium access control control element (MAC-CE) communication.

14. The method of claim 10, wherein transmitting the indication of the PUCCH resource comprises: transmitting, to the second UE, a downlink control information (DCI) communication that includes a sidelink transmit grant, associated with the sidelink data transmission, for the second UE, wherein the sidelink transmit grant includes the indication of the PUCCH resource.

15. A first user equipment (UE), comprising: one or more memories; and one or more processors, coupled to the one or more memories, configured to: receive an indication of a physical uplink control channel (PUCCH) resource for providing hybrid automatic repeat request (HARQ) feedback for a sidelink data transmission from a second UE; and transmit the HARQ feedback for the sidelink data transmission on the PUCCH resource.

16. The UE of claim 15, wherein the one or more processors are further configured to: transmit a copy of the HARQ feedback on a physical sidelink feedback channel

(PSFCH) to the second UE.

17. The UE of claim 15, wherein the one or more processors are further configured to: refrain from transmitting a copy of the HARQ feedback on a physical sidelink feedback channel (PSFCH) to the second UE.

18. The UE of claim 15, wherein the one or more processors, to receive the indication of the PUCCH resource, are configured to: receive, from a base station, a downlink control information (DCI) communication that includes a sidelink receive grant for the first UE, wherein the sidelink receive grant includes the indication of the PUCCH resource and an indication that the second UE is to transmit the sidelink data transmission to the first UE.

19. The UE of claim 18, wherein the DCI communication is a DCI format 3 0 communication.

20. The UE of claim 15, wherein the one or more processors, to receive the indication of the PUCCH resource, are configured to: receive, from a base station, a downlink communication that includes the indication of the PUCCH resource, wherein the downlink communication is a radio resource control (RRC) communication or a medium access control control element (MAC-CE) communication.

21. The UE of claim 15, wherein the one or more processors, to receive the indication of the PUCCH resource, are configured to: receive, from the second UE, a sidelink control information (SCI) communication, associated with the sidelink data transmission, that includes the indication of the PUCCH resource.

22. The UE of claim 15, wherein the one or more processors, to transmit the HARQ feedback on the PUCCH resource, are configured to: transmit the HARQ feedback on the PUCCH resource to a base station associated with the first UE and the second UE.

23. The UE of claim 15, wherein the one or more processors, to transmit the HARQ feedback on the PUCCH resource, are configured to: transmit the HARQ feedback on the PUCCH resource to a first base station associated with the first UE, wherein the HARQ feedback is for a second base station associated with the second UE, and wherein the first base station and the second base station are different base stations.

24. A base station, comprising: one or more memories; and one or more processors, coupled to the one or more memories, configured to: transmit a downlink communication that includes an indication of a physical uplink control channel (PUCCH) resource for a first user equipment (UE) to provide hybrid automatic repeat request (HARQ) feedback for a sidelink data transmission from a second UE; and receive the HARQ feedback for the sidelink data transmission from the first UE on the PUCCH resource.

25. The base station of claim 24, wherein the one or more processors, to transmit the indication of the PUCCH resource, are configured to: transmit, to the first UE, a downlink control information (DCI) communication that includes a sidelink receive grant for the first UE.

26. The base station of claim 25, wherein the sidelink receive grant includes the indication of the PUCCH resource and an indication that the second UE is to transmit the sidelink data transmission to the first UE.

27. The base station of claim 25, wherein the DCI communication is a DCI format 3 0 communication.

28. The base station of claim 24, wherein the one or more processors, to transmit the indication of the PUCCH resource, are configured to: transmit, to the first UE, the downlink communication that includes the indication of the PUCCH resource, wherein the downlink communication is a radio resource control (RRC) communication or a medium access control control element (MAC-CE) communication.

29. The base station of claim 24, wherein the one or more processors, to transmit the indication of the PUCCH resource, are configured to: transmit, to the second UE, a downlink control information (DCI) communication that includes a sidelink transmit grant, associated with the sidelink data transmission, for the second UE.

30. The base station of claim 29, wherein the sidelink transmit grant includes the indication of the PUCCH resource.